Precancerous growths, small areas of discrete roughness to the skin, come from too much sun, note VA researcher Basil M. Hantash, MD, PhD, and colleagues. Particularly when a person has a lot of them, they tend to become squamous cell carcinomas: cancer.

Doctors often burn off these growths, called actinic keratoses, with liquid nitrogen. But there's evidence other ways of removing them work at least as well.

Also, the other techniques appear to do another very important thing: They slow the development of cancer.

Hantash, of Palo Alto, Calif., and colleagues compared three of these techniques in 24 men. The patients had an average age of 73; all but three had previously had skin cancers removed. Five similar patients served as an untreated comparison group.

Before treatment, the 24 men had dozens of precancerous facial growths.

The researchers treated the men with laser resurfacing, an acid skin peel, or a topical cream containing fluorouracil, a chemotherapy drug.

All treatments worked, reducing the number of precancerous skin growths by 83% (chemo cream), 89% (skin peel), and 92% (laser).

Preventing New Cancers

The treatments also seemed to slow the development of new skin cancers.

Left untreated, the patients would be expected to develop 1.7 new facial skin cancers a year.

That's pretty close to what happened in the untreated comparison group. But the treated patients had only 0.04 to 0.22 new skin cancers per year.

"In the ... acid peel arm, one cancer per 26.1 years would be expected, compared with 1 cancer per 6.79 and 4.77 years in the [laser] and [chemo cream] arms, respectively," Hantash and colleagues report.

The untreated comparison group, they calculated, had 1.57 new cancers per year: that is, one new cancer every eight months.

The patients who got the acid peel were much more compliant with treatment, and had fewer side effects than those treated with laser or chemo cream.

Hantash and colleagues note that repeated treatments may be needed. In any case, patients with precancerous facial growths must get careful follow-up care.

Because the study had several limitations -- including its small size, infrequent use of sunscreen, and a control group that was not randomly picked -- the researchers warn that their findings must be confirmed in larger studies.

Hantash and colleagues report their research in the August issue of the Archives of Dermatology.